Some processing rules for the Spark engine differ from the processing rules for the Data Integration Service.
Mapping Validation
Mapping validation fails in the following situations:
Case sensitivity is disabled.
The lookup condition contains binary data type.
The lookup condition uses a field with a complex data type.
The cache is configured to be shared, named, persistent, dynamic, or uncached. The cache must be a static cache.
The mapping fails in the following situation:
The transformation is unconnected and used with a Joiner or Java transformation.
Multiple Matches
When you choose to return the first, last, or any value on multiple matches, the Lookup transformation returns any value.
If you configure the transformation to report an error on multiple matches, the Spark engine drops the duplicate rows and does not include the rows in the logs.
If an HBase lookup does not result in a match, it generates a row with null values for all columns. You can add a Filter transformation after the Lookup transformation to filter out null rows.